Price & comfort difference between Gambrel and Attic

[murd]

Looking to get some opinions on our planned build. We're looking at a 24 x 30 with a second floor. I had originally planned on Gambrel trusses for upstairs.
Before I totally commit to that, I wanted to see if the roof of an attic truss garage would be cheaper to install (both labour and materials) and roughly how much. There's no issue with building height where we are, and the larger floor area of the gambrel would probably be a big benefit. Just second guessing my plans for upstairs.

So anyone have thoughts on it? Done one and should have done the other?

Thanks

 

[kaymccampbell]

I like gambrel. Makes for comfortable living quarters. Attic trusses, not so much.

 

[MushCreek]

My barn is gambrel. Lots of room in the loft. I used barnplans.com. You build the four walls and loft deck, then build the trusses on the loft floor and stand them up. Lots of good ideas on their website even if you don't use their plans, although the plans are very reasonable, IMO.

 

[jack stand]

If you "boil it down" the main difference is (usually) can you live with some posts and a beam downstairs. Attic trusses will span without but the usable space is smaller.
Is this a garage or shop building? Personally a 2nd floor in a utility type building ends up being a not so handy closet to throw **** into and I'd spend that money on a bigger footprint. For a house, the gambrell is the winner.

 

[dfiler2]

You don't need posts with either design on a 24' wide building. You will get more room upstairs with the gambrel style roof. It probably comes down to how you will use the space.

 

[theoldwizard1]

My 2¢. I like gambrel roofs, BUT the mid span angle needs to be 45° !

 

[jack stand]

You don't need posts with either design on a 24' wide building. You will get more room upstairs with the gambrel style roof. It probably comes down to how you will use the space.

How are you going to span 24' of living space?

 

[WisJim]

My 24 by 40 building has gambrel trusses with attic room about 14 feet wide with 7+' ceiling height, mostly set up for my wife's loom, spinning wheels, sewing, etc., with a smaller room for shelving for back issues of magazines. The trusses span the 24 feet and are designed for a 40psf live load.

 

[murd]

The drawings I've been given both designs span the 24' without posts downstairs.

My 2¢. I like gambrel roofs, BUT the mid span angle needs to be 45° !

Just wondering why you say that? They have the gambrel marked as 12/12 so that would give a 45, right? The attic trusses are 10/12 pitch. This was one of the considerations aside from cost and usable area, the angle on the 12/12 lines up with where solar panels should be, but that's for future plans.

 

[Sumboodie]

How are you going to span 24' of living space?

TJIs?

 

[dfiler2]

There are certainly a number of ways to span 24' without posts upstairs or down but I was referring to the lower garage area being post free in my first post.

 

[jar944]

TJIs?

14 or 16".. or a center beam.

 

[BFBOB]

Not to be nitpicking or anything... but the photo (of a terrific garage!) you show is actually a Mansard roof. The difference is the pitch of the lower roof. In a Mansard, it's close to vertical, while in Gambrel designs it's much shallower. I don't know what the exact dividing point between the two is, but yours is clearly a Mansard.
Historically, the Mansard was developed in London long ago because of the taxation of buildings. Tell the tax collector, No, that's not a wall, it's a steep roof. So that's not a second story, it's just an attic. Lower taxes.

More
Just because... I did a little more research, and according to another source, the difference between the two roof types is gables. The Gambrel has four pitched areas (with two different pitches) and a gable at each end. The Mansard has eight pitched areas (with two different pitches), and no gables. Roof all the way around.
Like the difference between a pitched roof and a hip roof.

I don't know which is really correct. Heck, both could be correct in different areas of the globe!

 

[MushCreek]

The pitches on my roof are 12/7 and 7/12, or roughly 30 degree cuts. My barn is 28' wide; the usable loft is 20' wide, with an 8'+ headroom. There is lots of storage space under the roof slopes as well.